A fine single Pd microwire H 2 sensor fabricated by using a femtosecond laser for a wide detection range at room temperature.

We reported a fine H 2 sensor based on single Pd microwires (SPMs) by femtosecond-laser-induced deposition of palladium nanoparticles (PdNPs), which exhibits excellent H 2 sensing performance. The PdNPs with good dispersion were prepared by ultrasonic assisted one-step solution synthesis. The sensor has a wide detection range of 0.001-4.0% H 2 sensing at room temperature. With the increase of the H 2 concentration, the SPM sensor presents two sensing mechanisms, the formation of PdH x and hydrogen induced lattice expansion regulating the conductivity of SPMs. This fine hydrogen sensor is promising to be applied to human health monitoring, environmental air detection and other integrated intelligent devices.